Laundry dryer with heat shield

ABSTRACT

A laundry dryer is provided including a dryer casing with a drum for receipt of articles for drying positioned therein. The laundry dryer also includes a heating system positioned in the dryer casing, the heating system including an evaporator configured to cool and dehumidify air from the drum and a heating element configured to heat air provided to the drum. The laundry dryer also includes features for hindering a transfer of an extreme temperature condition from the drum to the heating system.

FIELD OF THE INVENTION

The present subject matter relates generally to a laundry dryer, or more particularly to a laundry dryer utilizing a heat shield.

BACKGROUND OF THE INVENTION

A conventional appliance for drying articles, such as a laundry dryer (or clothes dryer), typically includes a cabinet including a rotating drum for tumbling clothes and laundry articles therein. One or more heating elements heats air prior to air entering the drum, and the warm air is circulated through the drum as the clothes are tumbled to remove moisture from laundry articles in the drum. A gas or electric heater may be used to heat air that is circulated through the drum.

In a known operation, ambient air from outside is drawn into the cabinet and passed through the heater before being fed to the drum. Moisture from the clothing is transferred to the air passing through the drum. Typically, this moisture laden air is then transported away from the dryer by, e.g., a duct leading outside of the structure or room where the dryer is placed. The exhausted air removes moisture from the dryer and the clothes are dried as the process is continued by drawing in more ambient air.

Unfortunately, for the conventional dryer described above, the exhausted air is still relatively warm while the ambient air drawn into the dryer must be heated. This process is relatively inefficient because heat energy in the exhausted air is lost and additional energy must be provided to heat more ambient air. More specifically, the ambient air drawn into the dryer is heated to promote the liberation of the moisture out of the laundry. This air, containing moisture from the laundry, is then exhausted into the environment along with much of the heat energy that was used to raise its temperature from ambient conditions.

One alternative to a conventional dryer as described above is a heat pump dryer. More specifically, a heat pump dryer uses a refrigeration cycle to both provide hot air to the dryer and to condense water vapor in air coming from the dryer. Because the moisture content in the air from the dryer is reduced by the condensation over the evaporator, this same air can be reheated again and passed through the dryer to remove more moisture. Because the air is recycled through the dryer in a closed loop rather than being ejected to the environment, the heat pump dryer can be more efficient to operate than the traditional dryer described above.

However, certain components of the heat pump dryer can be susceptible to damage in extreme temperature conditions that may form in the drum of the laundry dryer. Accordingly, a heat pump clothes dryer capable of protecting certain components from extreme temperature conditions in the drum of the laundry dryer would be useful.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one exemplary embodiment of the present disclosure, a laundry dryer is provided including a dryer casing, a drum positioned in the dryer casing for receipt of articles for drying, and a refrigerant based heating system positioned in the dryer casing. The refrigerant based heating system includes a compressor, an evaporator configured to cool and dehumidify air from the drum, and a condenser configured to heat air provided to the drum. The laundry dryer additionally includes a shield positioned within the dryer casing between the compressor, the evaporator, and the condenser of the refrigerant based heating system and the drum comprised of a flame-resistant material.

In another exemplary embodiment of the present disclosure, a flame shield for a laundry dryer is provided, the flame shield including a first side configured to be positioned adjacent to a refrigerant based heating system of the laundry dryer. The refrigerant based heating system includes a compressor, a condenser, and an evaporator. The flame shield additionally includes a second and opposite side configured to be positioned adjacent to a drum of the laundry dryer, and a perimeter defining a shape that corresponds to a perimeter of the refrigerant based heating system, such that the flame shield is configured to protect the refrigerant based heating system during extreme temperature conditions.

In still another exemplary embodiment of the present disclosure, a laundry dryer is provided, the laundry dryer including a dryer casing, a drum positioned in the dryer casing for receipt of articles for drying, and a heating system positioned in the dryer casing. The heating system includes an evaporator configured to cool and dehumidify air from the drum and an electrical resistance heater configured to heat air provided to the drum. The laundry dryer additionally includes a shield positioned within the dryer casing between the evaporator and the electrical resistance heater of the heating system and the drum comprised of a flame-resistant material.

These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

FIG. 1 provides a front view of a laundry dryer appliance according to an exemplary embodiment of the present subject matter.

FIG. 2 provides a front cutaway view of the exemplary laundry dryer appliance of FIG. 1.

FIG. 3 provides a schematic view of certain components of a refrigerant based heating system according to an exemplary embodiment of the present subject matter.

FIG. 4 provides a front perspective view of a bottom portion of the exemplary laundry dryer appliance of FIG. 1 with a front panel, a drum, and a shield removed.

FIG. 5 provides a front perspective view of a bottom portion of the exemplary laundry dryer appliance of FIG. 1 with the front panel and drum removed, and including a shield according to an exemplary embodiment of the present subject matter.

FIG. 6 provides a side schematic view of certain components of the exemplary laundry dryer depicted in FIG. 5.

FIG. 7 provides a side schematic view of certain components of an end of a shield according to another exemplary embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIGS. 1 and 2 illustrate an exemplary embodiment of a heat pump laundry dryer appliance 10 of the present invention. More particularly, FIG. 1 provides a front view of the dryer 10, and FIG. 2 provides a cutaway view of the dryer 10 of FIG. 1, showing various internal components. While described in the context of a specific embodiment of a laundry dryer 10, using the teachings disclosed herein it will be understood that dryer 10 is provided by way of example only. Other heat pump dryers having different appearances and different features may also be utilized with the present invention as well.

The dryer 10 includes a dryer casing or main housing 12 and defines a vertical direction V, a lateral direction L, and a transverse direction T, each orthogonal to one another. The dryer casing 12 includes a front panel 14, a rear panel 16, a pair of side panels 18 and 20 spaced apart from each other by front and rear panels 14 and 16, a bottom panel 22 (see FIGS. 4 and 5), and a top cover 24. Within the dryer casing 12 is a drum or container 26 mounted for rotation around a substantially horizontal axis. A motor (not shown) rotates the drum 26 about the horizontal axis through a pulley and a belt (also not shown). The drum 26 depicted is generally cylindrical in shape, having an imperforate outer cylindrical wall 28, a perforated inner cylindrical wall 29, and a front flange or wall 30. More particularly, the inner wall 29 defines a plurality of perforations 36, and the front flange 30 defines an opening 32 for loading and unloading, e.g., clothing articles and other laundry articles. In other embodiments of the invention, however, the outer cylindrical wall 28 may also be perforated.

A plurality of tumbling ribs 27 are provided within the drum 26 to lift clothing articles therein and then allow them to tumble back to the bottom of the drum 26 as the drum 26 rotates. The drum 26 additionally includes a rear wall 34 rotatably supported within the dryer casing 12 by a suitable fixed bearing. The rear wall 34 can be fixed or can be rotatable. Moreover, the rear wall 34 includes a plurality of holes or perforations 37 that receive hot air. The hot air is heated by a heat pump heating system, also known as a refrigerant based heating system 40 (discussed in greater detail below). Accordingly, the laundry dryer 10 may be referred to as a heat pump laundry dryer, or a refrigerant based heating system laundry dryer. Moisture laden, heated air is drawn from drum 26 through a collection duct 42 after passing through a screen filter 46 which traps lint particles. As will be discussed in greater detail below, moisture is removed from the air drawn from the drum 26 through filter screen 46 by the refrigerant based heating system 40, and returned to the drum 26 via a supply duct 44 as heated air (with a lower moisture content than was previously received from drum 26) through the holes 37 in the rear wall 34. A door 33 provides for closing or accessing drum 26 through opening 32.

Referring still to FIGS. 1 and 2, a cycle selector knob 70 is mounted on a cabinet backsplash 71 and is in communication with a processing device or controller 72. Signals generated in controller 72 operate a drum drive system and heating system in response to the position of selector knobs 70. Additionally, or alternatively, a touch screen type interface may be provided.

The controller 72 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a drying cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 72 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. The cycle selector knob 70 and other components of dryer 10 may be in communication with controller 72 via one or more signal lines or shared communication busses.

Referring now to FIG. 3, is a schematic representation of an exemplary embodiment of the refrigerant based heating system 40 as may be used with clothes dryer 10 is provided. During steady state operating conditions, moisture laden air (arrow E) received from drum 26 is caused to flow across an evaporator 116, where the temperature of the air is reduced through heat exchange with evaporator 116, or more particularly with the refrigerant that is vaporized within, e.g., coils or tubing of the evaporator 116. This vaporization process absorbs both the sensible and the latent heat from the moisture laden air—thereby reducing its temperature. As a result, moisture in the air is condensed and is drained out using a drain line (not shown).

Air passing over the evaporator 116 becomes drier and cooler than when it was received from drum 26 of dryer 10. As shown by arrow C, the air from evaporator 116 is subsequently caused to flow across a condenser 104 (e.g., across coils or tubing of the condenser 104). As used herein, it should be understood that the term “condenser” also includes one or more gas coolers and other heat exchangers for cooling and/or condensing the refrigerant. The refrigerant in the condenser 104 may be in a gaseous state at a relatively high temperature compared to the air from evaporator 116. As a result, heat energy is transferred to the air, thereby elevating its temperature and providing warm air for resupply to the drum 26 of dryer 10. Because the same air is recycled through drum 26 and heating system 40, dryer 10 can have a much greater efficiency than traditional clothes dryers where warm, moisture laden air is exhausted to the environment.

Continuing with FIG. 3, the heat pump 40 additionally includes a compressor 100 that pressurizes refrigerant, i.e., increases the pressure of the refrigerant supplied by a suction line 120. Compressor 100 may be designed to pressurize a gas phase refrigerant. Accordingly, refrigerant in suction line 120 may be supplied in a gas phase. The pressurization of the refrigerant with compressor 100 increases the temperature of the refrigerant. Accordingly, by a line 102, the compressed refrigerant may be fed to the condenser 104. As relatively cooler air having already passed over the evaporator 116 (arrow C) is passed over the condenser 104, the air is heated and the refrigerant is cooled. More particularly, the temperature of the refrigerant is lowered as heat is transferred to the air for supply to drum 26.

Upon exiting condenser 104, the refrigerant is fed by a line 110 to an expansion device 113. Although only one expansion device 113 is shown, such is by way of example only, it being understood that multiple such devices may additionally be used. The expansion device 113 lowers the pressure of the refrigerant and controls the amount of refrigerant that is allowed to enter the evaporator 116 by a line 114. Notably, the flow of liquid refrigerant into the evaporator 116 may be limited by the expansion device 113 in order to keep the pressure low and allow expansion of the refrigerant back into a gas phase in the evaporator 116. The evaporation of the refrigerant in the evaporator 116 converts the refrigerant from its liquid-dominated phase to a gas phase while cooling the air (arrow E) from drum 26. The process is repeated as air is circulated through drum 26 and between evaporator 116 and gas cooler 104 while the refrigerant is cycled as just described.

Referring now to FIG. 4, a portion of the dryer 10 of FIGS. 1 and 2 is depicted. More particularly, FIG. 4 provides a perspective view of a bottom portion of the clothes dryer 10, with the front panel 14, the drum 26, and a shield 136 (see FIG. 5) removed. The heat pump 40 is depicted defining an air inlet 124 for receiving moisture laden air from the drum 26 via the collection duct 42 and an air outlet 126 for providing the heated and dehumidified air from the heat pump 40 back to the drum 26 via the supply duct 44. The airflow through the refrigerant based heating system 40 is provided by a first blower 128 and a second blower 130. An electric motor 132 is also included, the electric motor mechanically engaged with the heating system 40. More particularly, the first blower 128 and second blower 130 are each powered by the electric motor 132. The first blower 128 pulls airflow from the drum 26 through the duct 42, into the refrigerant based heating system 40 and over the evaporator 116. Additionally, the second blower 130 pulls airflow across the condenser 104 and provides such airflow back to the drum 26 through the supply duct 44.

The electrical motor 132 may also supply mechanical energy to other components of the refrigerant based heating system 40. For example, the electric motor 132 may also provide mechanical energy to the compressor 100 of the refrigerant based heating system 40. It should be appreciated, however, that in other exemplary embodiments, any other suitable mechanism(s) may be provided for creating an airflow through the refrigerant based heating system 40 and/or for powering the first blower 128 and/or the second blower 130. For example, in other exemplary embodiments, the motor that rotates the drum 26 of the laundry dryer 10 may provide the requisite mechanical energy.

The refrigerant based heating system 40 is depicted with certain components positioned in a heater casing 134. More particularly, the exemplary dryer 10 of FIG. 4 includes the compressor 100, the evaporator 116, and the condenser 104 of the refrigerant based heating system 40 in the heater casing 134. The heater casing 134 provides the requisite ductwork to allow the cooling and dehumidification of air from the drum 26, as well as the reheating of air provided back to the drum 26. Additionally, the heater casing 134 may be comprised of any suitable material, such as a flame resistant plastic material having a “V-0” rating or better based on the UL 94 Standard for Safety of Flammability of Plastic Materials for Parts in Devices and Appliances testing, as released by the Underwriters Laboratories of the USA. Although, in other embodiments, any other suitable material may be used.

The electric motor 132 and FIG. 4 is positioned in approximately the same plane (perpendicular to the vertical direction V) as certain components of the refrigerant based heating system 40 and the heater casing 134. However, in other exemplary embodiments, the electric motor 132 may instead be positioned at any other suitable location within the dryer casing 12, such as below the refrigerant based heating system 40 and heater casing 134. By being positioned in the approximately the same plane as the heating system 40, the dryer 10 may define a more compact design.

It should be appreciated, however, that the refrigerant based heating system 40 is provided by way of example only. In other exemplary embodiments, for example, the dryer may instead include any other suitable means for cooling and dehumidifying the air from the drum 26, and any other suitable means for reheating the air to be provided to the drum 26. For example, in certain exemplary embodiments, the dryer may not include the refrigerant based heating system 40, and instead may include any suitable evaporator/heat exchanger for cooling and dehumidifying the air from the drum 26, and an electrical resistance heater, such as an electric coil, for reheating air to be provided to the drum 26. Operation of such a evaporator/heat exchanger may be similar to the evaporator 116 described above, except instead of cool refrigerant passing through condenser coils, relatively cool ambient air may be passed through the condenser coils. In such an exemplary embodiment, the heat exchanger and electrical resistance heater may be positioned in the heater casing 134 described above.

Referring now to FIG. 5, the dryer 10 is depicted further including a means for hindering a transfer of an extreme temperature condition from the drum 26 to the refrigerant based heating system 40. More particularly, FIG. 5 depicts the dryer 10 including a means for hindering a transfer of an extreme temperature condition from the drum 26 to the compressor 100, the evaporator 116, and the condenser 104 of the refrigerant based heating system 40. For the exemplary embodiment shown, the means for hindering the transfer of an extreme temperature condition is a shield 136 including a flame resistant material. The shield 136 is positioned within the dryer casing 12 between the compressor 100, the evaporator 116, the condenser 104, and the expansion device 113 of the refrigerant based heating system 40 and the drum 26 of the laundry dryer 10. More particularly, the drum 26 is positioned above the shield 136 along the vertical direction V of the laundry dryer 10, while the various components of the refrigerant based heating system 40 are positioned below the shield 134 along the vertical direction V of the laundry dryer 10. In such an exemplary embodiment the shield 136 may be positioned directly adjacent to, i.e., in contact with, the heater casing 134 enclosing the various components of the refrigerant based heating system 40. By contrast, however, the laundry dryer 10 may include a gap along the vertical direction V between the shield 136 and the drum 26.

Referring still to FIG. 5, the shield 136 includes a flexible material 138 positioned adjacent to the heater casing 134. In certain exemplary embodiments, the flexible material 138 of the shield 136 may be a fiberglass fabric material. However, in other exemplary embodiments, any other suitable flexible and flame resistant material 138 may be used. The flexible material 138 of the shield 136 may allow the shield 136 to conform to a shape of the refrigerant based heating system 40, or more particularly, to a shape of the heater casing 134 (as is depicted in FIG. 5).

The shield 136 also defines a perimeter 140, which in turn defines a shape that corresponds approximately to a perimeter of the refrigerant based heating system 40. For example, the perimeter 140 of the shield 136 is configured to extend around an outside of the electric motor 132 in a plane perpendicular to the vertical direction V, and accordingly the shield 136 defines a cutout portion 142 through which the electric motor 132 extends. Such a configuration may allow the electric motor 132 to receive a flow of ambient air to maintain a desired operating temperature. It should be appreciated that, as used herein, terms of approximation, such as “approximately” or “substantially,” refer to being within a 10% margin of error.

Moreover, the shield 136 depicted includes a frame 144 extending around at least a portion of the perimeter 140 of the shield 136. The frame 144 may be made of a rigid material, such as a metal or hard plastic. Alternatively, the frame may be made of a semi-rigid material, allowing for some flexibility or an increased elastic deformation, while still providing structure for the shield 136. For the exemplary embodiment of FIG. 5, the frame 144 extends around the entirety of the perimeter 140 of the shield 136. However, in other exemplary embodiments, the frame 144 may instead only extend around a portion of the perimeter 140 of the shield 136, such as along one side of the perimeter 140 of the shield 136 or along two opposing sides of the perimeter 140 of the shield 136. Inclusion of a frame 144 may assist in assembling the dryer 10, by keeping the shield 136 in a desired shape such that a user may simply place the shield 136 in position over the refrigerant based heating system 40 within the dryer casing 12.

Referring now also to FIG. 6, wherein a side schematic view of certain components of a portion of the dryer appliance 10 is depicted, the frame 144 of the shield 136 is attached to the dryer casing 12. The dryer casing 12 is depicted including a first bracket 146 extending along an inside surface 148 of side panel 18 in the transverse direction T, and a second bracket 150 (FIG. 5) extending along an inside surface 152 of the side panel 20, also in the transverse direction T. More particularly, for the embodiment shown, the first bracket 146 and second bracket 150 are each L-shaped brackets. The frame 144 is positioned on the first and second brackets 146, 150 to maintain the shield 136 in position. Moreover, in certain embodiments, the frame 144 may be attached to the first and/or second bracket 146, 150 using any suitable attachment means, such as, for example, by using bolts, screws, rivets, or any suitable epoxy.

The exemplary laundry dryer 10 of the present disclosure additionally includes a temperature sensor 154 positioned on or within the dryer casing 12. For the embodiment depicted in FIG. 5, the temperature sensor 154 is positioned above the shield 136 along the vertical direction V of the laundry dryer 10 on an inside surface 156 of the back panel 16. However, in other exemplary embodiments, one or more temperature sensors may additionally or alternatively be positioned below the shield 136 along the vertical direction V of the laundry dryer 10. The temperature sensor 154 may be any suitable temperature sensor, such as, for example, a thermocouple, a thermistor, a resistance thermometer, a bimetallic sensor, or any other suitable temperature sensor.

In certain exemplary embodiments, the temperature sensor 154 may be operatively connected to, e.g., the controller 72 of the laundry dryer 10. Accordingly, the laundry dryer 10 may be configured to cease operation when the temperature sensor 154 senses a temperature above a predetermined threshold. Ceasing operation of the laundry dryer 10 may stop an airflow through the drum 26 and through the refrigerant based heating system 40. Accordingly, ceasing operation of the dryer 10 may include ceasing operation of the first and second blowers 128, 130. Moreover, the predetermined threshold may be, for example, a temperature at which further operation of the laundry dryer 10 may cause damage to the laundry dryer 10, such as a temperature indicative of an extreme temperature condition, e.g., an ember, being present in the drum 26. For example, the predetermined threshold may be approximately 212° F.

It should be appreciated, however, that the shield 136 described above with reference to FIGS. 5 and 6 is provided by way of example only. In other exemplary embodiments, the shield 136 may additionally or alternatively include any other suitable rigid or semi-rigid structure or configuration. For example, in other exemplary embodiments the shield 136 may additionally or alternatively include one or more crosswise brackets extending between opposite sides of the perimeter 140 of the shield 136 and attached to the frame 144 of the shield 136. Additionally, or alternatively, in other exemplary embodiments, shield 136 may not include a frame 144, and instead may simply be draped over the refrigerant based heating system 40 and heater casing 134. The shield 136 may additionally be configured to wrap-around one or more edges of the refrigerant based heating system 40 and heater casing 134 and, e.g., attach to the bottom panel 22. Moreover in still other exemplary embodiments, heater casing 134 may be made of two or more individual parts positioned in any suitable manner.

Referring now to FIG. 7, a cross-sectional side view of a portion of a shield in accordance with another exemplary embodiment of the present disclosure is provided. The exemplary shield 136 of FIG. 7 includes a first side configured to be positioned adjacent to the refrigerant based heating system 40 of the laundry dryer 10 and a second and opposite side configured to be positioned adjacent to a drum 26 of the laundry dryer 10. More particularly, for the exemplary embodiment depicted, the first side is the flexible layer 138 and the second side is a rigid layer 160. As discussed above, the flexible layer 138 may be any suitable flexible and flame resistant material, such as a fiberglass fabric material, while the rigid layer 160 may be any suitable material for providing structure and at least a minimal amount of rigidity for the shield 136. For example, the rigid layer 160 may be made of a thin sheet metal, a plastic material, or any other suitable material. The rigid layer 160 may define a shape substantially similar to the shape of a top portion of the heater casing 134, and may be formed by molding, machine pressing, stamping, or using any other suitable method. Additionally, as with the embodiment described above with reference to FIG. 6, the shield 136 may be positioned on and/or attached to the first and/or second brackets 146, 150 of the dryer 10 (see FIG. 5). It should be appreciated, however, that in other exemplary embodiments, the shield 136 may instead simply lay on the heater casing 134, or alternatively may be attached to the dryer casing 12 using any other suitable attachment means. Inclusion of a rigid layer 160 may assist a user in installing the shield 136 by allowing the user to place the shield 136 in position over the refrigerant based heating system 40 and heater casing 134.

Referring still to FIG. 7, the first side (the flexible layer 138) may be attached to the second side (the rigid layer 160) in any suitable manner. For example, the first side and second side may be attached using a glue or other epoxy, or one or more bolts, rivets, staples, or other mechanical attachment means. The entirety of the flexible layer 138 may be attached to the rigid layer 160. Alternatively, however, discrete parts, lines, or areas of the flexible layer 138 may be attached to the rigid layer 160.

A laundry dryer appliance 10 including the shield 136 described above with reference to FIGS. 5 and 6 and/or with reference to FIG. 7 may be better capable of handling an extreme temperature condition in the drum 26 of the laundry dryer 10. More particularly, a laundry dryer 10 in accordance with the present disclosure including the shield 136 described above may be more capable of preventing an extreme temperature condition from traveling from the drum 26 to one or more of the evaporator 116, the condenser 104, the compressor 100, and/or the expansion device 113 of the refrigerant based heating system 40, as well as to the heater casing 134.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other and examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 

What is claimed:
 1. A laundry dryer comprising: a dryer casing; a drum positioned in the dryer casing for receipt of articles for drying; a refrigerant based heating system positioned in the dryer casing and including a compressor, an evaporator configured to cool and dehumidify air from the drum, and a condenser configured to heat air provided to the drum; and a shield positioned within the dryer casing between the compressor, the evaporator, and the condenser of the refrigerant based heating system and the drum comprised of a flame-resistant material.
 2. The laundry dryer of claim 1, wherein the shield comprises a flexible material.
 3. The laundry dryer of claim 2, wherein the flexible material is a fiberglass fabric.
 4. The laundry dryer of claim 1, wherein the shield includes a frame extending at least partially around a perimeter of the shield.
 5. The laundry dryer of claim 4, wherein the frame is attached to the dryer casing.
 6. The laundry dryer of claim 1, wherein the laundry dryer defines a vertical direction, and wherein the drum is positioned above the shield along the vertical direction.
 7. The laundry dryer of claim 1, further comprising a heater casing, wherein the compressor, the evaporator, and the condenser of the refrigerant based heating system are positioned within the heater casing, and wherein the shield is positioned adjacent to the heater casing.
 8. The laundry dryer of claim 7, wherein the heater casing is comprised of a flame resistant plastic material.
 9. The laundry dryer of claim 1, further comprising an electric motor mechanically engaged with the refrigerant based heating system, wherein the shield extends around the electric motor.
 10. The laundry dryer of claim 1, wherein the shield comprises a rigid layer attached to a flexible layer.
 11. The laundry dryer of claim 10, wherein the rigid layer is a metal layer and wherein the flexible layer is a fiberglass fabric layer.
 12. The laundry dryer of claim 10, further comprising a gap defined between the rigid layer and the drum.
 13. The laundry dryer of claim 1, further comprising a temperature sensor positioned on or within the dryer casing, the laundry dryer configured to cease operation when the temperature sensor senses a temperature above a predetermined threshold.
 14. The laundry dryer of claim 13, wherein the temperature sensor is positioned above the shield along a vertical direction of the laundry dryer.
 15. A flame shield for a laundry dryer comprising: a first side configured to be positioned adjacent to a refrigerant based heating system of the laundry dryer, the refrigerant based heating system including a compressor, a condenser, and an evaporator; a second and opposite side configured to be positioned adjacent to a drum of the laundry dryer; and a perimeter defining a shape that corresponds to a perimeter of the refrigerant based heating system, such that the flame shield is configured to prevent a transfer of an extreme temperature condition from the drum to the refrigerant based heating system.
 16. The flame shield of claim 15, further comprising a rigid frame attached to the perimeter of the flame shield.
 17. The flame shield of claim 15, wherein the first side is a flexible layer, and wherein the second side is a rigid layer.
 18. A laundry dryer comprising: a dryer casing; a drum positioned in the dryer casing for receipt of articles for drying; a heating system positioned in the dryer casing and including an evaporator configured to cool and dehumidify air from the drum and an electrical resistance heater configured to heat air provided to the drum; and a shield positioned within the dryer casing between the evaporator and the electrical resistance heater of the heating system and the drum comprised of a flame-resistant material.
 19. The laundry dryer of claim 18, wherein the heating system is positioned within a heater casing, the heater casing positioned in the dryer casing, and wherein the shield comprises a flexible material.
 20. The laundry dryer of claim 18, wherein the laundry dryer further comprises an electric motor positioned approximately in the same plane as the heating system, and wherein the shield defines a cutout configured to extend around the electric motor. 